Simpler Rules: Rule 18

Rule 18: Ball at Rest Moved 

18-1. By Outside Agency

If a ball at rest is moved or caused to be moved by an outside agency, it must be replaced, unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made. 

Note: It is a question of fact whether a ball has been moved by an outside agency. In order to apply this Rule, there must be conclusive evidence that an outside agency has moved the ball. In the absence of such knowledge or certainty, the player must play the ball as it lies or, if the ball is not found, proceed under Rule 27-1. 

(Player’s ball at rest moved by another ball – see Rule 18-5)

 

18-2. By Player, Partner, Caddie or Equipment

a. General

Except as permitted by the Rules, when a player’s ball is in play, if 

(i)    the player, his partner or either of their caddies:  

•    lifts or moves the ball,

•    touches it purposely (except with a club in the act of addressing the ball), or

•    causes the ball to move, or  

(ii)   the equipment of the player or his partner moves or causes the ball to move,  

the player incurs a penalty of one stroke. 

If the ball is moved, it must be replaced, unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made. 

Under the Rules there is no penalty if a player accidentally moves or causes his ball to move in the following circumstances: 

•   In searching for a ball covered by sand, in the replacement of loose impediments moved in a hazard while finding or identifying a ball, in probing for a ball lying in water in a water hazard or in searching for a ball in an obstruction or an abnormal ground condition – Rule 12-1

•   In repairing a hole plug or ball mark –Rule 16-1c

•   In measuring –Rule 18-6

•   In lifting a ball under a Rule – Rule 20-1

•   In placing or replacing a ball under a Rule–Rule 20-3a

•   In removing a loose impediment on the putting green – Rule 23-1

•   In removing movable obstructions – Rule 24-1

 

b. Ball Moving After Address

If a player’s ball in play moves after he has addressed it (other than as a result of a stroke), unless there is conclusive evidence that the player did not cause his ball to move, the player is deemed to have moved the ball and incurs a penalty of one stroke. 

The ball must be replaced, unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made.

 

18-3. By Opponent, Caddie or Equipment in Match Play

a. During Search

If, during search for a player’s ball, an opponent, his caddie or his equipment moves the ball, touches it or causes it to move, there is no penalty. If the ball is moved, it must be replaced. 

b. Other Than During Search

If, other than during search for a player’s ball, an opponent, his caddie or his equipment moves the ball, touches it purposely or causes it to move, except as otherwise provided in the Rules, the opponent incurs a penalty of one stroke. If the ball is moved, it must be replaced unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made. 

(Playing a wrong ball – see Rule 15-2)

(Ball moved in measuring – see Rule 18-6)

 

18-4. By Fellow-Competitor, Caddie or Equipment in Stroke Play

If a fellow-competitor, his caddie or his equipment moves the player’s ball, touches it or causes it to move, there is no penalty. If the ball is moved, it must be replaced unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made. 

(Playing a wrong ball – see Rule 15-2)

 

18-5. By Another Ball

If a ball in play and at rest is moved or caused to be moved by another ball in motion after a stroke, the moved ball must be replaced unless the movement of the ball occurs after the player has begun the stroke or the backward movement of the club for the stroke and the stroke is made.

 

18-6. Ball Moved in Measuring

If a ball or ball-marker is moved in measuring while proceeding under or in determining the application of a Rule, the ball or ball-marker must be replaced. There is no penalty, provided the movement of the ball or ball-marker is directly attributable to the specific act of measuring. Otherwise, the provisions of Rule 18-2a, 18-3b or 18-4 apply. 

*PENALTY FOR BREACH OF RULE:

Match play – Loss of hole; Stroke play – Two strokes. 

*If a player who is required to replace a ball fails to do so, or if he makes a stroke at a ball substituted under Rule 18 when such substitution is not permitted, he incurs the general penalty for breach of Rule 18, but there is no additional penalty under this Rule. 

Note 1: If a ball to be replaced under this Rule is not immediately recoverable, another ball may be substituted. 

Note 2: If the original lie of a ball to be placed or replaced has been altered, see Rule 20-3b.

Note 3: If it is impossible to determine the spot on which a ball is to be placed or replaced, see Rule 20-3c.